"For the first time, a federal appeals court has ruled that law enforcement must obtain a warrant to get people’s phone location histories from their cell service companies."Source & full article at https://www.aclu.org/technology-and-liberty/first-time-appeals-court-rules-warrant-required-cell-phone-location-tracking
PDF of the ruling itself at https://www.aclu.org/sites/default/files/assets/q_davis_opinion_0.pdf
A little hope, my understanding is that this ruling would only apply to jurisdiction of the court that made the ruling, and I suspect governments (local/state/federal?) will appeal.